The bond companies were subpoenaed in order to gather more
information about their dealings with banks. The six banks that
have also been subpoenaed as part of the process, according to
Bloomberg are: Goldman Sachs, Bank of America, and Morgan
Stanley, and most recently, JPMorgan, Deutsche Bank, and UBS.

The bond companies claim that banks deceived them into
guaranteeing worthless loans. Some of the bond companies, like
MBIA, for example, have filed lawsuits against the banks
demanding that they re-purchase the loans. (One lawsuit unveiled
a $1 million loan to a stripper.)